Explicitly provide identical sized original/alternative instruction
sequences. This way there is no need for the s390 specific alternatives
infrastructure to generate padding sequences.
The code which generates such sequences will be removed with a follow on
patch.
Signed-off-by: Heiko Carstens <[email protected]>
---
arch/s390/include/asm/spinlock.h | 2 +-
arch/s390/kernel/entry.S | 20 ++++++++++----------
arch/s390/lib/spinlock.c | 4 ++--
3 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h
index 10a460762e94..37127cd7749e 100644
--- a/arch/s390/include/asm/spinlock.h
+++ b/arch/s390/include/asm/spinlock.h
@@ -79,7 +79,7 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp)
typecheck(int, lp->lock);
kcsan_release();
asm_inline volatile(
- ALTERNATIVE("", ".insn rre,0xb2fa0000,7,0", 49) /* NIAI 7 */
+ ALTERNATIVE("nop", ".insn rre,0xb2fa0000,7,0", 49) /* NIAI 7 */
" sth %1,%0\n"
: "=R" (((unsigned short *) &lp->lock)[1])
: "d" (0) : "cc", "memory");
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 685ccec02a27..a6b45eaa3450 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -53,19 +53,19 @@ STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
_LPP_OFFSET = __LC_LPP
.macro STBEAR address
- ALTERNATIVE "", ".insn s,0xb2010000,\address", 193
+ ALTERNATIVE "nop", ".insn s,0xb2010000,\address", 193
.endm
.macro LBEAR address
- ALTERNATIVE "", ".insn s,0xb2000000,\address", 193
+ ALTERNATIVE "nop", ".insn s,0xb2000000,\address", 193
.endm
.macro LPSWEY address,lpswe
- ALTERNATIVE "b \lpswe", ".insn siy,0xeb0000000071,\address,0", 193
+ ALTERNATIVE "b \lpswe; nopr", ".insn siy,0xeb0000000071,\address,0", 193
.endm
.macro MBEAR reg
- ALTERNATIVE "", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK), 193
+ ALTERNATIVE "brcl 0,0", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK), 193
.endm
.macro CHECK_STACK savearea
@@ -121,16 +121,16 @@ _LPP_OFFSET = __LC_LPP
.endm
.macro BPOFF
- ALTERNATIVE "", ".insn rrf,0xb2e80000,0,0,12,0", 82
+ ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,12,0", 82
.endm
.macro BPON
- ALTERNATIVE "", ".insn rrf,0xb2e80000,0,0,13,0", 82
+ ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,13,0", 82
.endm
.macro BPENTER tif_ptr,tif_mask
ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .insn rrf,0xb2e80000,0,0,13,0", \
- "", 82
+ "j .+12; nop; nop", 82
.endm
.macro BPEXIT tif_ptr,tif_mask
@@ -226,7 +226,7 @@ ENTRY(__switch_to)
aghi %r3,__TASK_pid
mvc __LC_CURRENT_PID(4,%r0),0(%r3) # store pid of next
lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
- ALTERNATIVE "", "lpp _LPP_OFFSET", 40
+ ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40
BR_EX %r14
ENDPROC(__switch_to)
@@ -610,7 +610,7 @@ ENTRY(mcck_int_handler)
jno 0f
BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP
stpt __LC_EXIT_TIMER
-0: ALTERNATIVE "", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA),193
+0: ALTERNATIVE "nop", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA),193
LBEAR 0(%r12)
lmg %r11,%r15,__PT_R11(%r11)
LPSWEY __LC_RETURN_MCCK_PSW,__LC_RETURN_MCCK_LPSWE
@@ -646,7 +646,7 @@ ENTRY(mcck_int_handler)
ENDPROC(mcck_int_handler)
ENTRY(restart_int_handler)
- ALTERNATIVE "", "lpp _LPP_OFFSET", 40
+ ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40
stg %r15,__LC_SAVE_AREA_RESTART
TSTMSK __LC_RESTART_FLAGS,RESTART_FLAG_CTLREGS,4
jz 0f
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index 5e7ea8b111e8..04d4c6cf898e 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -75,7 +75,7 @@ static inline int arch_load_niai4(int *lock)
int owner;
asm_inline volatile(
- ALTERNATIVE("", ".insn rre,0xb2fa0000,4,0", 49) /* NIAI 4 */
+ ALTERNATIVE("nop", ".insn rre,0xb2fa0000,4,0", 49) /* NIAI 4 */
" l %0,%1\n"
: "=d" (owner) : "Q" (*lock) : "memory");
return owner;
@@ -86,7 +86,7 @@ static inline int arch_cmpxchg_niai8(int *lock, int old, int new)
int expected = old;
asm_inline volatile(
- ALTERNATIVE("", ".insn rre,0xb2fa0000,8,0", 49) /* NIAI 8 */
+ ALTERNATIVE("nop", ".insn rre,0xb2fa0000,8,0", 49) /* NIAI 8 */
" cs %0,%3,%1\n"
: "=d" (old), "=Q" (*lock)
: "0" (old), "d" (new), "Q" (*lock)
--
2.32.0
On Wed, May 11, 2022 at 02:05:25PM +0200, Heiko Carstens wrote:
> Explicitly provide identical sized original/alternative instruction
> sequences. This way there is no need for the s390 specific alternatives
> infrastructure to generate padding sequences.
> The code which generates such sequences will be removed with a follow on
> patch.
>
> Signed-off-by: Heiko Carstens <[email protected]>
> ---
> arch/s390/include/asm/spinlock.h | 2 +-
> arch/s390/kernel/entry.S | 20 ++++++++++----------
> arch/s390/lib/spinlock.c | 4 ++--
> 3 files changed, 13 insertions(+), 13 deletions(-)
Acked-by: Vasily Gorbik <[email protected]>